The disclosures of U.S. Pat. No. 5,197,685, granted Mar. 30, 1993 to Alvin C. Banner, and U.S. Pat. No. 5,340,043, granted Aug. 23, 1994 to John M. Beakes and Lawrence E. Newman, are hereby incorporated by reference herein.
This invention relates to a method and apparatus for winding stators for dynamoelectric devices and, although not so limited, especially to a method and apparatus for winding two pole stators.
This invention is intended for use with well known methods and apparatus for winding stators wherein coils of wire drawn from sources of wire under tension are wound around the pole pieces on a laminated stator core by a reciprocating and oscillating winding head or ram. The winding head or ram is driven by a mechanism such as that shown in U.S. Pat. No. 4,158,314. A common practice when winding two pole stators in this fashion is to use two pairs of oppositely directed shrouds or winding forms, one pair for each pole, that guide the wire segments exiting from the winding head around the pole pieces. The shrouds or winding forms are usually secured to the stator by pairs of form-retaining clamps or blades but it has been recognized that there are disadvantages to the use of the form retaining blades. The manipulations required to operate the blades or clamps are time-consuming and significantly limit production speeds. In addition, space for insertion of the blades must necessarily be provided by a gap between the end faces of the stator core and the coil end turns, a factor which can have a negative effect upon the characteristics of the wound coils. For another thing, there have been reports that compounds used to trickle impregnate the stator coils occasionally flow through the gap into the bore of the stator.
The aforementioned Banner ""685 patent discloses winding forms provided with mutually-engaging latching members which interconnect a pair of cooperating winding forms. A spring acting on one of the latch members serves to bias the winding forms into engagement with the stator assembly. The Banner ""685 winding forms are designed for winding stators of the type having coil support extensions connected to the pole pieces and extending from both end faces of the stator for the purpose of supporting the stator coil end turns. The coil support extensions have outwardly directed coil-retaining fingers spaced from the end faces of the stator core. The winding forms are provided with pockets which receive the coil retaining fingers for preventing the winding forms from moving radially inwardly when stator coils are being wound. A drawback to the use of the Banner ""685 winding forms is that their use required changes in the winding form-handling carriages that load the winding forms onto a stator being wound and unload them from a newly wound stator.
The Beakes et al. ""043 patent discloses improved winding form assemblies which, as in the Banner ""685 assemblies, rely on pockets that receive coil-retaining fingers for preventing the winding forms from moving inwardly of the bore of the stator. The Beakes et al. ""043 invention solved shortcomings of the Banner ""685 construction, as is described in the Beakes et al. ""043 patent. A significant aspect of the Beakes et al. ""043 construction was that clamp assemblies held by the female winding forms clamped against surfaces of alignment pins or connecting rods on the male winding forms extended into cooperating apertures in the female winding forms. Because of this construction, the male winding forms could be entirely conventional and both the male and the female winding forms could be manipulated by the same winding form loading and unloading carriages as are used in loading and unloading winding forms that do not have clamps for holding them together. However, the Beakes et al. ""043 construction has not been entirely satisfactory. This is partly because the alignment pin clamps do not hold as reliably as they should for high speed, mass production purposes, probably due to vibrations experienced by the winding forms. Also, the coil support extensions and their coil-retaining fingers may bend and permit the winding forms disclosed in both the Banner ""685 patent and the Beakes et al. ""043 patent to move into the bore of the stator. And, of course, the Banner ""685 and the Beakes et al. ""043 winding forms can only be used with stators having coil-support extensions with coil-retaining fingers.
A primary object of this invention is to provide a method and apparatus for winding a two pole stator utilizing shrouds or winding forms which may be rapidly and securely assembled onto a stator core and rapidly disassembled from the stator core. A related object of this invention is to provide a method and an apparatus for winding stators using winding forms that do not require the use of form retaining blades. A further object of this invention is to provide a method and apparatus wherein the steps of assembly and disassembly of the winding forms on the stator cores can be accomplished automatically.
A more specific object of this invention is to provide an improved method and apparatus for supporting stator winding forms on stators which may be used when winding stators which do not have coil-supporting extensions. Yet another object of this invention is to provide an improved method and apparatus for clamping mutually-cooperating winding forms onto a stator core without the use of form retaining blades whereby the forms are reliably retained during high speed stator winding procedures.
In accordance with this invention, a winding form assembly including a pair of winding forms used to wind a stator coil around a pole piece are supported against radial inward movement by the pole piece. A simple and reliable latch mechanism holds the two winding forms together. As in the case of the Beakes et al. ""043 construction, standard winding form handling mechanism, which has carriage-mounted support pins protruding into the winding forms, can be used to move the winding forms into position on the stator to be wound. The latch mechanisms inside each pair of cooperating winding forms lock or latch them together automatically as the winding forms are moved into position on the stator to be wound. After placement of the winding forms into proper position, the support pins are removed from the winding forms and backed out of the way for subsequent winding operations. After winding, the support pins are again inserted into the winding forms, the latch mechanisms automatically unlocked, and the forms removed from the winding area. The next stator is then moved into the winding station. Winding form latching and unlatching are caused by, and occur during, movements of the support pins into and out of the winding forms and do not require any machine cycle time separate from the cycle time taken for the carriages to manipulate the winding forms.
Two embodiments of clamp mechanisms are disclosed, one in which the release member is slidably confined within the female winding form and the other in which the release member is pivotally mounted within the winding form.
Other objects and advantages will become apparent from the following description and the drawings.